Method of obtaining titanium oxide



Patented Dec. 18, 1 928.

UNITED STATES PATENT OFFICE.

REGINALD-HILL MONK, OF MONTREAL, QUEBEC, CANADA.

METHOD OF OBTAINING TITANIUM OXIDE.

No Drawing.

This invention relates to the treatment of minerals and products thereof containing titanium, such as ilmenite, rutile after the elimination of impurities and a large portion of the iron content, and particularly titanium concentrates such as are obtained by the process described in U. S. Patent No. 1,543,250,

16th June 1925.

The object of my invention is to convert such refractory compoundsof titanium into a water soluble compound, or compounds. This I propose to do ,by the use of a mixture of sulphuric acid with an alkali metaLsulphate, at a temperature lower than that at tanium oxide especially suited for use as a.

white pigment. The solution obtained by my invention possesses new and desirable qualities whereby is assured the precipitation of titanium compounds entirely free from ims purities, such as iron, which causes discoloration of the final product. a

The solution obtained is novel in itself, as hydrolysis may be carried out at a very low temperature. Providing the iron present has previously been reduced to the ferrous state, the compound of titanium obtained on hydrolysis is entirely free from impurities.

' The temperature employed is so low that the ferrous iron is not oxidized during the process, and no hydrolysis of iron salts takes place.

I am aware that various patents have been granted for the sulphating of titanium ores and the products thereof, but these processes are invariably carried out at relatively high temperatures at which fusion occurs.

The melt obtained from the employment of such substances as concentrated sulphuric acid or sodium bisulphate, or combinations of these two, does not produce a large proportion of water soluble sulphates if a high temperature is used.

This is more particularly shown in the case of the above mentioned titanium concentrates obtainedby the process described in Letters Patent No. 1,543,250.

Application filed July 7, 1926. Serial No. 121,058.

WVhen rutile, or other refractory minerals and products thereof, have been subjected to a temperature around 1000 C. the process of direct treatment with concentrated sulphuric acid decomposes only a small percentage of the titanium present, and fusion of the residue at comparatively high temperatures with salts of alkali metals does not result in the production of a large percentage of titanium compounds soluble in water.

This invention relates to a process in which one continuous operation only is carried out at a temperature much lower than is required when an alkali metal salt is used alone. .Furthermore, no other addition of acid is required in order to bring the titanium into aqueous solution. The process differs from that using sulphuric acid only, as in addition to sul-' phuric acid large quantities of sodium sulphate are employed. The acid alone reacts with only a small percentage of the titanium present,whereas the use of the sodium acid sulphate and sulphuric acid mixture, as described, effects acomplete decomposition of the titanium oxides.

The process differs from fusion with acid alkali metal sulphates-alone, since in addition to such sulphates, sulphuric acid is also employed, and during the treatment the op-' timum temperature leading to the formation of soluble titanium compound is employed. This temperature is about 160 C. below that at which the sodium acid sulphate fuses,

which'is 300 C.

Furthermore, practically no acid isdriven off, and the titanium is entirely solublein water without any addition of acid. At the low temperature employed no alkali titanites are formed. v

In order to fully describe my invention I state the following example: a

From a titanium concentrate, obtained by the process described in Patent N 0. 1,543,250, containing 19.93% total iron, .7 metallic iron, and 54.62% TiO I take 400 grams, mix this with 600 grams of NaI-ISO and 840 grams H 66.43%. This mixture is now heated to 120 (3., being agitated the meanwhile. The mass is kept-below 140 C. for three hours. When it shows a tendency to solidify it is transferred on to a flat tray,

ously reduced to the ferrous state.

Resulting solution contains:

Grams pcrlitre.

no, 71.2 S0 80ml)"; 33 Na S 4 99 perature gradually, and finally bring it up to 95 (1., or thereabouts, for the last 20 to 30 minutes. I In this manner a pure compound of titanium is precipitated, and all the iron is kept in solution.

l Vhat I claim is i 1. The method of converting refractory compounds of titanium after the elimination of impurities and a large portion of the iron content into'water soluble sulphates, comprising mixing'the comminuted compound with an alkali-metal sulphate and an acid solvent, heating the mixture at a temperature from 120 to 000 C., until a solid cake is formed, cooling and crushing the cake.

2. The method of. converting refractory compounds of titanium after the elimination of impurities and a large portion of the iron content into water soluble sulphates, comprising mixing the comminuted compound with an alkali-metal sulphate and an acid solvent, heating the mixture at first below 140 C. transferring to a tray and raising the temperature to about 260 C. until a solid cake is formed, cooling and crushing the cake and lixiviatin'g with cold water.

The method of obtaining titanium oxide from concentrates containing titanium and iron which comprises, mixing the comminuted material with an alkali-metal sulphate and an acid solvent, heating the mixture at a temperature from 120 to 300 C. until a solid cake is formed, cooling and crushing the cake and lixiviating with cold water, and

precipitating the titanium oxide from the solution.

4. The method of obtaining titanium oxide from concentrates containing titanium and iron which comprises mixing the comreoaeai minuted material with an alkali-metal sulphate and an acid solvent, heating the mixture at a temperature from 120 to 300 C. until a solid cake is formed, cooling and crushing the cake, lixiviating with cold water and hydrolyzing the solution at a low temperature.

5. The method of obtaining titanium oxide from concentrates containing titanium and iron which comprises, mixing the comminuted substance with an alkali-metal sulphate and an acid solvent, heating the mixture below 140 C. transferring the mass to a tray and raising the temperature to about 260 C. until a solid cake is formed, cooling and crushing the cake, lixiviating with cold water and precipitating the titanium oxide from the solution. p

6. The method of obtaining titanium oxide from concentrates containing titanium and iron which comprises, mixing the comminuted substance with an alkali-metal sulphate and an acid solvent, heating the mixture below 140 C. transferring the mass to a tray and raising the temperature to about 260 C. until a solid cake is formed, cooling and crushing the cake, lixiviating with cold water, reducing the iron to the ferrous state and precipitating'the titanium oxide from the solution.

7 The method of obtaining titanium oxide from concentrates containing titanium and iron which comprises, mixing the comminuted material with approximately one and one half times by weight of an alkalianeta] sulphate and double the weight of sulphuric acid, heating the mixture to below 140 C. until it begins to solidify, heating on a fiat tray up to 260 C. till a solid cake is formed, cooling and crushing the cake and then lixiviating withcold water and precipitating the titanium oxidefrom the solution.

8. The method of obtaining titanium oxide from concentrates containing titanium and iron which comprises, mixing the comminuted, material with approximately one and a half times by weight of an alkali-metal sulphateand double the weight of sulphuric acid, heating the mixture to below 140 C. until it begins to solidify, heating on a flat tray up to 260 C. till a solid cake is formed, coolingand crushing the cake and then lixiviating with cold water and hydrolyzing the solution at not over C. and gradually to about 95 C.

REGINALD HILL MONKI 

